26
Transforms and Partial Differential Equations 2019 Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 1 SUBJECT NAME : Transforms and Partial Differential Equations SUBJECT CODE : MA8353 MATERIAL NAME : University Questions REGULATION : R2017 WEBSITE : www.hariganesh.com UPDATED ON : November - December 2019 TEXTBOOK FOR REFERENCE : Sri Hariganesh Publications (Author: C. Ganesan) To buy the book visit www.hariganesh.com/textbook Unit I (Partial Differential Equations) Formation of PDE and Standard Types of PDE 1. Find the partial differential equation of all planes which are at a constant distance ‘ a from the origin. (A/M 2010),(A/M 2017) Text Book Page No.: 1.25 2. Form the PDE by eliminating the arbitrary function from 2 2 2 , 0 x y z ax by cz . (N/D 2010),(M/J 2012) Text Book Page No.: 1.18 Video Explanations 3. Form the partial differential equation by eliminating arbitrary functions f and from ( ) ( ) z fx ct x ct . (A/M 2011) Text Book Page No.: 1.20 4. Form the PDE by eliminating the arbitrary functions ‘ f ’ and ‘ g ’ from 2 2 () () z xf y ygx . (N/D 2013) Text Book Page No.: 1.23 5. Form the PDE by eliminating the arbitrary function from the relation 2 1 2 log z y f y x . (M/J 2014) Text Book Page No.: 1.16

Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

  • Upload
    others

  • View
    18

  • Download
    0

Embed Size (px)

Citation preview

Page 1: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 1

SUBJECT NAME : Transforms and Partial Differential Equations

SUBJECT CODE : MA8353

MATERIAL NAME : University Questions

REGULATION : R2017

WEBSITE : www.hariganesh.com

UPDATED ON : November - December 2019

TEXTBOOK FOR REFERENCE : Sri Hariganesh Publications (Author: C. Ganesan) To buy the book visit www.hariganesh.com/textbook

Unit – I (Partial Differential Equations)

Formation of PDE and Standard Types of PDE

1. Find the partial differential equation of all planes which are at a constant distance ‘ a ’

from the origin. (A/M 2010),(A/M 2017)

Text Book Page No.: 1.25

2. Form the PDE by eliminating the arbitrary function from

2 2 2, 0x y z ax by cz . (N/D 2010),(M/J 2012)

Text Book Page No.: 1.18 Video Explanations

3. Form the partial differential equation by eliminating arbitrary functions f and from

( ) ( )z f x ct x ct . (A/M 2011)

Text Book Page No.: 1.20

4. Form the PDE by eliminating the arbitrary functions ‘ f ’ and ‘ g ’ from

2 2( ) ( )z x f y y g x . (N/D 2013)

Text Book Page No.: 1.23

5. Form the PDE by eliminating the arbitrary function from the relation

2 12 logz y f y

x

. (M/J 2014)

Text Book Page No.: 1.16

Page 2: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 2

6. Find the singular solution of 2 2z px qy p q . (N/D 2014),(N/D 2017)

Text Book Page No.: 1.39

7. Solve 2 2z px qy p q . (N/D 2009),(A/M 2015)

Text Book Page No.: 1.44

8. Find the singular integral of 2 21z px qy p q .

(N/D 2011),(M/J 2013),(N/D 2013),(M/J 2016)

Text Book Page No.: 1.40 Video Explanations

9. Find the singular integral of 2 2z px qy p pq q .

(N/D 2012),(A/M 2017),(A/M 2018)

Text Book Page No.: 1.47

10. Solve 1p q qz (A/M 2010)

Text Book Page No.: 1.52

11. Solve 2 2 2 2p q x y (A/M 2010)

Text Book Page No.: 1.61

12. Solve 2 2 2 2 2z p q x y . (N/D 2011)

Text Book Page No.: 1.69

13. Solve 2 2 2 2 2x p y q z . (M/J 2014)

Text Book Page No.: 1.71

14. Obtain the complete solution of 2 2 2 2 2 2p x y q x z . (A/M 2015)

Text Book Page No.: 1.74

Page 3: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 3

PDE of Lagrange’s Linear Equation

1. Solve the partial differential equation ( ) ( )mz ny p nx z q y mx .(A/M 2011)

Text Book Page No.: 1.94

2. Solve the partial differential equation 2 2 2x y z p y z x q z x y .

(N/D 2010),(M/J 2012)

Text Book Page No.: 1.101

3. Solve ( ) ( ) ( )x y z p y z x q z x y . (N/D 2011),(N/D 2014),(A/M 2018)

Text Book Page No.: 1.97

4. Solve 2 2 2 2 2 2x y z p y z x q z x y . (N/D 2011),(M/J 2013),(A/M 2017)

Text Book Page No.: 1.99 Video Explanations

5. Solve ( 2 ) (2 )x z p z y q y x . (N/D 2012),(N/D 2017)

Text Book Page No.: 1.103

6. Solve ( ) ( ) ( )( )y xz p yz x q x y x y . (N/D 2009)

Text Book Page No.: 1.105

7. Solve 2 20y z p xyq xz . (N/D 2013)

Text Book Page No.: 1.106

8. Solve 2 2 2x yz p y zx q z xy . (A/M 2010),(A/M 2015),(M/J 2016)

Text Book Page No.: 1.110

9. Solve the Lagrange’s equation 22 2x z p xz y q x y . (M/J 2014)

Text Book Page No.: 1.108

10. Find the general solution of 2 22z yz y p xy zx q xy zx .(A/M 2017)

Page 4: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 4

Homogeneous Linear Partial Differential Equation

1. Solve 2 2 22 sinh( )

x yD DD D z x y e

. (N/D 2009)

Text Book Page No.: 1.132

2. Solve 2 22 x yD DD D z e xy . (N/D 2017)

3. Solve 2 2 22

x yD DD D z x y e

. (A/M 2017)

4. Solve 2 2 2 42 2 3

x yD DD D z x y e

. (N/D 2013)

Text Book Page No.: 1.149

5. Solve 3 2 2 34 4 cos 2D D D DD D z x y . (N/D 2010),(M/J 2012)

Text Book Page No.: 1.145

6. Solve 3 2 37 6 sin 2D DD D z x y . (M/J 2013)

Text Book Page No.: 1.175

7. Solve 3 2 37 6 sin 2D DD D z x y . (N/D 2014)

Text Book Page No.: 1.143 Video Explanations

8. Solve 2 2 24 5 sin( 2 )

x yD DD D z x y e

. (A/M 2018)

Text Book Page No.: 1.159

9. Solve 3 2 2 22 2 3

xD D D z e x y . (N/D 2011),(M/J 2016)

Text Book Page No.: 1.175

10. Solve 2 3 22

x yD DD z x y e

. (N/D 2014)

Text Book Page No.: 1.157

11. Solve 2 23 4 cos 2D DD D z x y xy . (N/D 2012)

Text Book Page No.: 1.159

Page 5: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 5

12. Solve 3 2 37 6 cos 2D DD D z x y x . (N/D 2011)

Text Book Page No.: 1.175

13. Solve: 2 2 23 2 (2 4 )

x yD DD D z x e

. (A/M 2015)

Text Book Page No.: 1.168

14. Solve 2 26 cosD DD D z y x . (M/J 2013),(M/J 2014),(N/D 2016),(A/M 2018)

Text Book Page No.: 1.170

15. Solve 2 25 6 sinD DD D z y x . (N/D 2017)

Non Homogeneous Linear Partial Differential Equation

1. Solve 2 2 22 3 3 2

x yD DD D D D z e

. (N/D 2011)

Text Book Page No.: 1.184 Video Explanations

2. Solve 2 22 4

x yD DD D z e

. (N/D 2012)

Text Book Page No.: 1.183

3. Solve 2 22 2 2 sin( 2 )D DD D D D z x y . (A/M 2010),(M/J 2016)

Text Book Page No.: 1.188

4. Solve 2 23 3 7D D D D z xy . (N/D 2009)

Text Book Page No.: 1.190

5. Solve 2 22 6 3

yD DD D D D z xe . (N/D 2010),(M/J 2012)

Text Book Page No.: 1.195

6. Solve 2 23 2 2 2 sin(2 )D DD D D D z x y x y .

Text Book Page No.: 1.192 (A/M 2011),(A/M 2017)

Page 6: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 6

Unit – II (Fourier Series)

Fourier Series in the interval (0,2ℓ)

1. Expand ( ) 2f x x x as Fourier series in 0,2 and hence deduce that the

sum of 2 2 2 2

1 1 1 1...

1 2 3 4 . (A/M 2011)

Text Book Page No.: 2.6

2. Find the Fourier series of 2

( )f x x in 0,2 of periodicity 2 .

(M/J 2012)

Text Book Page No.: 2.3

3. Find the Fourier series of period 2 for the function ( ) cosf x x x in 0 2x .

(A/M 2017)

4. Find the Fourier series expansion of for 0

( )2 for 2

x xf x

x x

. Also, deduce

that 2

2 2 2

1 1 1...

1 3 5 8

. (N/D 2010)

Text Book Page No.: 2.12

5. Find the Fourier Series Expansion of 1 for 0

( )2 for 2

xf x

x

. (N/D 2013)

Text Book Page No.: 2.10

6. Find the Fourier series for a function , 0

( )0, 2

x xf x

x

in 0,2 .(N/D 2017)

7. Find the Fourier expansion of , 0 1

( )2 , 1 2

x xf x

x x

. Also, deduce

2

2 2 2

1 1 1...

1 3 5 8

. (N/D 2012)

Text Book Page No.: 2.38

Page 7: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 7

8. Obtain the Fourier series of periodicity 3 for 2( ) 2f x x x in 0 3x .

(N/D 2011)

Text Book Page No.: 2.33

Fourier Series in the interval (-ℓ,ℓ)

1. Find the Fourier series of ( )f x x in x . (M/J 2016)

2. Find the Fourier series of 2x in x . Hence deduce the value of

21

1

n n

and

4

4 4 4

1 1 1...

1 2 3 90

. (N/D 2014),(M/J 2013),(N/D 2016),(A/M 2018)

Text Book Page No.: 2.42

3. Obtain the Fourier series of ( ) sinf x x x in , . (N/D 2011)

Text Book Page No.: 2.47

4. Obtain the Fourier series to represent the function ( )f x x , x and

deduce

2

21

1

82 1n n

. (M/J 2012)

Text Book Page No.: 2.45

5. Find the Fourier series of ( ) sinf x x in x of periodicity 2 . (A/M 2015)

Text Book Page No.: 2.51

6. Find the Fourier series expansion of ( ) cosf x x in x . (M/J 2016)

7. Obtain the Fourier series for the function ( )f x given by1 , 0

( )1 , 0

x xf x

x x

.

Hence deduce that2

2 2 2

1 1 1...

1 3 5 8

. (A/M 2011)

Text Book Page No.: 2.61

Page 8: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 8

8. Find the Fourier series expansion of 1, 0

( )1, 0

x xf x

x x

. (N/D 2013)

Text Book Page No.: 2.61

9. Expand

21 , - 0

( )2

1 , 0

xx

f xx

x

as a full range Fourier series in the interval

, . Hence deduce that 2

2 2 2

1 1 1...

1 3 5 8

. (M/J 2014)

Text Book Page No.: 2.58

10. Find the Fourier series expansion of 2( )f x x x in , . (N/D 2012),(N/D 2017)

Text Book Page No.: 2.62

Half Range Fourier Series

1. Find the half-range cosine series for ( )f x x in 0, . Hence deduce the value of

2 2 2

1 1 1...

1 3 5 . (N/D 2017)

2. Find the half range cosine series of the function ( ) ( )f x x x in the interval

0 x . Hence deduce that4

4 4 4

1 1 1...

1 2 3 90

. (A/M 2010),(A/M 2018)

Text Book Page No.: 2.108

3. Find the half-range Fourier cosine series of 2

( )f x x in the interval (0, ) .

Hence find the sum of the series 4 4 4

1 1 1...

1 2 3 . (M/J 2012)

Text Book Page No.: 2.95

4. Obtain the Fourier cosine series of 2

1 , 0 1x x and hence show that

2

2 2 2

1 1 1...

1 2 3 6

. (M/J 2013),(N/D 2014)

Text Book Page No.: 2.88

Page 9: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 9

5. Obtain the half range cosine series for ( )f x x in 0, . (N/D 2010),(N/D 2012)

Text Book Page No.: 2.81

6. Find the Fourier half-range cosine series of , 0 1

( )2 - , 1 2

x xf x

x x

. (A/M 2017)

7. Find the half-range sine series of , 0 / 2

( )- , / 2

x xf x

x x

. Hence deduce the sum

of the series 2

1

1

(2 1)n n

. (A/M 2015)

Text Book Page No.: 2.109

8. Obtain the Fourier cosine series expansion of sinx x in 0, and hence find the value

of 2 2 2 2

1 ...1.3 3.5 5.7 7.9

. (N/D 2011)

Text Book Page No.: 2.83

9. Find the half-range sine series of 2( ) 4f x x x in the interval 0,4 . Hence deduce

the value of the series 3 3 3 3

1 1 1 1...

1 3 5 7 . (M/J 2014)

Text Book Page No.: 2.109

10. Obtain the Fourier cosine series expansion of ( )f x x in 0 4x . Hence deduce the

value of 4 4 4

1 1 1...

1 3 5 . (N/D 2014)

Text Book Page No.: 2.98

11. Obtain the Fourier cosine series for

in 02

( )

in 2

kx x

f x

k x x

. (M/J 2013)

Text Book Page No.: 2.91

Page 10: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 10

Complex Form of Fourier Series

1. Find the complex form of the Fourier series of ( )ax

f x e , x .(A/M 2010)

Text Book Page No.: 2.113

2. Find the complex form of the Fourier series of ( )ax

f x e in, x . (N/D 2016)

3. Find the complex form of the Fourier series of ( )ax

f x e in, x . (A/M 2017)

4. Find the complex form of the Fourier series of ( )x

f x e in 1 1x .

(N/D 2009),(A/M 2015)

Text Book Page No.: 2.117

5. Find the complex form of Fourier series of cosax in , , where " "a is not an

integer. (M/J 2013)

Text Book Page No.: 2.115

6. Expand ( ) sinf x x as a complex form Fourier series in , . (M/J 2014)

Text Book Page No.: 2.124

Harmonic Analysis

1. Compute upto first harmonics of the Fourier series of ( )f x given by the following table

x 0 T/6 T/3 T/2 2T/3 5T/6 T

( )f x 1.98 1.30 1.05 1.30 – 0.88 – 0.25 1.98

(N/D 2009),(N/D 2011)

Text Book Page No.: 2.131

2. Find the Fourier series as far as the second harmonic to represent the function ( )f x

with the period 6, given in the following table.

(N/D 2009),(N/D 2010),(M/J 2012),(N/D 2012),(N/D 2016),(A/M 2017)

x 0 1 2 3 4 5

( )f x 9 18 24 28 26 20

Text Book Page No.: 2.129

Page 11: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 11

3. Find the Fourier cosine series up to third harmonic to represent the function given by the

following data: (M/J 2016)

x 0 1 2 3 4 5

( )f x 9 18 24 28 26 20

4. Find the Fourier series up to second harmonic for ( )y f x from the following values.

x: 0 π/3 2 π/3 π 4π/3 5 π/3 2 π

y: 1.0 1.4 1.9 1.7 1.5 1.2 1.0

(A/M 2011),(N/D 2013),(M/J 2014),(N/D 2014),(A/M 2015),(N/D 2017),(A/M 2018)

Text Book Page No.: 2.127

5. Calculate the first 3 harmonics of the Fourier of ( )f x from the following data

x : 0 30 60 90 120 150 180 210 240 270 300 330

( ) :f x 1.8 1.1 0.3 0.16 0.5 1.3 2.16 1.25 1.3 1.52 1.76 2.0

(N/D 2011)

Text Book Page No.: 2.133

Unit – III (Application of Partial Differential Equation)

One Dimensional Wave Equation with No Velocity

1. A string is stretched and fastened to points at a distance apart. Motion is started by

displacing the string in the form sinx

y a

, 0 x , from which it is released

at time 0t . Find the displacement at any time t . (M/J 2014)

Text Book Page No.: 3.21

2. A tightly stretched string with fixed end points 0x and x is initially in a position

given by 3

0( ,0) sin

xy x y

. It is released from rest from this position. Find the

expression for the displacement at any time t . (N/D 2012)

Text Book Page No.: 3.24

3. A uniform string is stretched and fastened to two points ‘ ’ apart. Motion is started by

displacing the string into the form of the curve ( )y kx x and then released from

this position at time 0t . Derive the expression for the displacement of any point of

the string at a distance x from one end at time t .

Page 12: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 12

Text Book Page No.: 3.25

(A/M 2011),(N/D 2011),(N/D 2013),(A/M 2015),(N/D 2017),(A/M 2018)

4. A tightly stretched string of length ‘ ’ has its ends fastened at 0x and x . The

mid – point of the string is then taken to height ‘b’ and released from rest in that

position. Find the lateral displacement of a point of the string at time ‘t’ from the

instant of release. (A/M 2010)

Text Book Page No.: 3.27

5. A tightly stretched string of length 2 is fastened at both ends. The midpoint of the

string is displaced by a distance ‘b’ transversely and the string is released from rest in

this position. Find an expression for the transverse displacement of the string at any

time during the subsequent motion. (N/D 2010),(A/M 2017)

Text Book Page No.: 3.43

One Dimensional Wave Equation with Velocity

1. A tightly stretched string with fixed end points 0x and x is initially at rest in its

equilibrium position. If it is set vibrating giving each point a initial velocity 3 ( )x x ,

find the displacement. (N/D 2009)

Text Book Page No.: 3.36

2. A tightly stretched string between the fixed end points 0x and x is initially at

rest in its equilibrium position. If each of its points is given a velocity ( )kx x , find

the displacement ( , )y x t of the string. (M/J 2013)

Text Book Page No.: 3.44

3. A tightly stretched string of length ‘ ’ is initially at rest in its equilibrium position and

each of its points is given the velocity 3

0

0

sint

y xV

t

. Find the displacement

( , )y x t . (N/D 2011),(N/D 2014)

Text Book Page No.: 3.32

Page 13: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 13

4. Find the displacement of a string stretched between two fixed points at a distance of

2 apart when the string is initially at rest in equilibrium position and points of the

string are given initial velocities v where

in 0,

2in ,2

x

vx

, x being the

distance measured from one end.

One Dimensional Heat Equation with Both Ends Are

Change to Zero Temperature

1. Find the solution to the equation 2

2

2

u ua

t x

that satisfies the conditions

(0,t) 0, ( ,t) 0u u , for 0t and , 0 / 2

( ,0), / 2

x xu x

x x

.

(N/D 2013),(A/M 2015)

Text Book Page No.: 3.53

2. A rod, 30 cm long has its ends A and B kept at 20⁰C and 80⁰C respectively, until steady

state conditions prevail. The temperature at each end is then suddenly reduced to 0⁰C

and kept so. Find the resulting temperature function is a regular function ( , )u x t taking

0x at A. (N/D 2009)

Text Book Page No.: 3.57

One Dimensional Heat Equation with Both Ends are Change

to Non Zero Temperature

1. A bar of 10 cm long, with insulated sides has its ends A and B maintained at temperatures

50 C and 100 C respectively, until steady-state conditions prevail. The temperature at

A is suddenly raised to 90 C and at B is lowered to 60 C . Find the temperature

distribution in the bar thereafter. (N/D 2011)(AUT)

Text Book Page No.: 3.53

2. A bar 10 cm long with insulated sides, has its ends A and B kept at 20 ˚C and 40 ˚C

respectively until steady state conditions prevail. The temperature at A is then suddenly

raised to 50 ˚C and at the same instant that at B is lowered to 10 ˚C. Find the subsequent

temperature at any point of the bar at any time. (A/M 2018)

Text Book Page No.: 3.59

Page 14: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 14

3. The ends A and B of a rod 40 cm long have their temperatures kept at 0˚C and 80˚C

respectively, until steady state condition prevails. The temperature of the end B is then

suddenly reduced to 40˚C and kept so, while that of the end A is kept at 0˚C. Find the

subsequent temperature distribution ( , )u x t in the rod. (M/J 2012)

Text Book Page No.: 3.59

4. A rod of length cm has its ends A and B kept at 0˚C and 100˚C respectively, until

steady state conditions prevail. If the temperature at B is suddenly reduced to 0˚C and

maintained at 0˚C, find the temperature distribution ( , )u x t at a distance x from A at

any time t . (N/D 2017)

Two Dimensional Heat Equation

1. A rectangular plate with insulated surface is 10 cm wide and so long compared to its

width that may be considered infinite in length without introducing appreciable error.

The temperature at short edge 0y is given by20 for 0 5

20(10 ) for 5 10

x xu

x x

and

the other three edges are kept at 0°C. Find the steady state temperature at any point in

the plate. (A/M 2010),(M/J 2013)

Text Book Page No.: 3.97

2. A rectangular plate with insulated surface is 20 cm wide and so long compared to its

width that it may be considered infinite in length without introducing an appreciable

error. If the temperature of the short edge 0x is given by

10 for 0 10

10(20 ) for 10 20

y yu

y y

and the two long edges as well as the other short

edge are kept at 0°C. Find the steady state temperature distribution in the plate.

(A/M 2011),(A/M 2017)

Text Book Page No.: 3.102

3. A square plate is bounded by the lines 0, 0, 20x y x and 20y . Its faces are

insulated. The temperature along the upper horizontal edge is given by

( ,20) (20 ),u x x x 0 20x while the other two edges are kept at 0 C . Find

the steady state temperature distribution in the plate.

Text Book Page No.: 3.83 (N/D 2010),(N/D 2011),(N/D 2016)

4. A square plate is bounded by the lines 0, , 0x x a y and y b . Its surfaces are

insulated and the temperature along y b is kept at 100˚C. While the temperature

Page 15: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 15

along other three edges are at 0˚C. Find the steady-state temperature at any point in

the plate. (N/D 2014)

Text Book Page No.: 3.88

5. Find the steady state temperature distribution in a rectangular plate of sides a and b

insulated at the lateral surfaces and satisfying the boundary conditions:

(0, ) ( , ) 0, for 0 ;u y u a y y b

( , ) 0 and ( ,0) ( ), for 0 .u x b u x x a x x a (N/D 2012)

Text Book Page No.: 3.78

6. A long rectangular plate with insulated surface is cm wide. If the temperature along

one short edge ( 0)y is 2( ,0) ( )u x k x x degrees, for 0 x , while the other

two long edges 0x and x as well as the other short edge are kept at 0˚C , find

the steady state temperature function ( , )u x y . (M/J 2012),(M/J 2016)

Text Book Page No.: 3.106

7. An infinitely long rectangular plate with insulated surfaces is 10cm wide. The two long

edges and one short edge are kept at 0˚C, while the other short edge 0x is kept at

temperature

20 , 0 5

20 10 , 5 10

u y y

u y y

. Find the steady state temperature

distribution in the plate. (M/J 2014)

Text Book Page No.: 3.110

Unit – IV (Fourier Transform)

Fourier Transform with Deduction

1. Find the Fourier transform of1 1

( )0 1

x if xf x

if x

and hence find the value of

4

4

0

sin

tdt

t

. (N/D 2009),(A/M 2010),(N/D 2011),(N/D 2012),(N/D 2016),(N/D 2017)

Text Book Page No.: 4.22

Page 16: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 16

2. Find the Fourier transform of1 1

( )0 1

x if xf x

if x

and hence find the value of i)

2

2

0

sin

tdt

t

ii) 4

4

0

sin

tdt

t

. (N/D 2014),(M/J 2016)

Text Book Page No.: 4.22

3. Find the Fourier transform of ( )f x given by 1 for

( )0 for 0

x af x

x a

and using

Parseval’s identity prove that

2

0

sin

2

tdt

t

. (A/M 2011)

Text Book Page No.: 4.20

4. Find the Fourier transform of1 for

( )0 for

x af x

x a

and hence evaluate0

sin xdx

x

.

Using Parseval’s identity, prove that 2

2

0

sin

2

tdt

t

.

Text Book Page No.: 4.20 (M/J 2013),(A/M 2015),(A/M 2017)

5. Find the Fourier transform of

21 1( )

0 1

x if xf x

if x

. Hence evaluate

3

0

cos sincos

2

x x x xdx

x

. (A/M 2011),(N/D 2013),(A/M 2018)

Text Book Page No.: 4.40

6. Show that the Fourier transform of

2 2 , ( )

0, 0

a x x af x

x a

is

3

2 sin cos2

as as as

s

. Hence deduce that3

0

sin cos

4

t t tdt

t

. Using

Perserval’s identity show that

2

3

0

sin cos

15

t t tdt

t

. (N/D 2011),(N/D 2012)

Text Book Page No.: 4.25 Video Explanations

Page 17: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 17

Integration using Parseval’s Identity

1. Evaluate

2

2 20

dx

x a

using Parseval’s identity. (M/J 2013),(N/D 2013),(M/J 2014)

Text Book Page No.: 4.50 Video Explanations

2. Using Parseval’s identity evaluate

2

22 2

0

xdx

x a

. (M/J 2014)

Text Book Page No.: 4.67

3. Find the Fourier sine and cosine transforms of a function xe . Using Parseval’s identity,

evaluate: (N/D 2017)

(i)

22

0 1

dx

x

and (ii)

2

22

0 1

x dx

x

4. Evaluate 2 2

0 1 4

dx

x x

using Fourier transforms. (A/M 2017)

Text Book Page No.: 4.52

5. Evaluate 2 2 2 2

0

dx

x a x b

using Fourier cosine transforms of ax

e and bx

e .

(N/D 2010),(A/M 2011),(N/D 2014)

Text Book Page No.: 4.67

Fourier Transform of Exponential Function&

Self Reciprocal Problems

1. Find the Fourier sine transform of axe and hence evaluate Fourier cosine transforms of

axxe

and sinax

e ax . (N/D 2011)

Text Book Page No.: 4.58

Page 18: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 18

2. Find the Fourier cosine and sine transforms of ( ) , 0ax

f x e a and hence deduce

the integrals 2 2

0

cos sxds

a s

and 2 2

0

sins sxds

a s

. (N/D 2012),(M/J 2016)

Text Book Page No.: 4.46

3. Find the Fourier sine transformation of ax

e

x

where 0a . (N/D 2011),(N/D 2016)

Text Book Page No.: 4.59

4. Find the function whose Fourier Sine Transform is 0as

ea

s

. (N/D 2013)

Text Book Page No.: 4.61

5. Show that the Fourier transform of

2

2

x

e

is

2

2

s

e

.

Text Book Page No.: 4.28 (A/M 2010),(M/J 2013),(M/J 2016),(A/M 2018)

6. Find the Fourier cosine transform of 2 2

, 0a x

e a . Hence show that the function

2

2

x

e

is self-reciprocal. (N/D 2012),(A/M 2017),(A/M 2018)

Text Book Page No.: 4.63

7. Find the Fourier transform of 2 2

, 0a x

e a . Hence show that the function

2

2

x

e

is self-

reciprocal under the Fourier transform. (N/D 2014),(A/M 2015),(N/D 2016)

Text Book Page No.: 4.28

8. Show that

2

2

x

e

is a self reciprocal with respect to Fourier transform. (N/D 2011)

Text Book Page No.: 4.28

9. Find the Fourier transform of 1

( )f xx

. (M/J 2014)

Text Book Page No.: 4.31

10. Find Fourier sine and cosine transform of 1nx

and hence prove 1

x is self reciprocal

under Fourier sine and cosine transforms. (M/J 2012),(A/M 2015)

Text Book Page No.: 4.64

Page 19: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 19

Fourier Transform of General Function& Derivations

1. Find the Fourier sine and cosine transform of sin , 0

( )0,

x x af x

x a

. (A/M 2010)

Text Book Page No.: 4.54

2. Find the Fourier integral representation of ( )f x defined as

0 for 0

1( ) for 0

2

for 0x

x

f x x

e x

.

Text Book Page No.: 4.33 (N/D 2010),(M/J 2012)

3. Find the Fourier sine transform of

, 0 1

( ) 2 , 1 2

0, 2

x x

f x x x

x

. (N/D 2010),(A/M 2011)

Text Book Page No.: 4.55

4. Solve for ( )f x from the integral equation 0

1, 0 1

( )sin 2, 1 2

0, 2

s

f x sx dx s

s

.

Text Book Page No.: 4.39 (M/J 2014)

5. Derive the Parseval’s identity for Fourier Transforms. (N/D 2010),(M/J 2012)

Text Book Page No.: 4.13

6. State and prove convolution theorem for Fourier transforms. (N/D 2011),(M/J 2012)

Text Book Page No.: 4.12

7. Verify the convolution theorem under Fourier Transform, for2

( ) ( ) ex

f x g x .

(M/J 2013)

Page 20: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 20

Unit – V (Z - Transforms)

Simple problems on Z - transforms

1. Find ( 1)( 2)Z n n n . (M/J 2012)

Text Book Page No.: 5.18

2. Find the Z – transform of 1

( 1)( 2)n n . (N/D 2013)

Text Book Page No.: 5.38

3. Find the Z – transform of 1

( 1)n n, for 1n . (N/D 2014),(M/J 2016)

Text Book Page No.: 5.14

4. Find the Z-transform of 2 3

( 1)( 2)

n

n n

. (A/M 2017),(N/D 2017)

5. Find cosZ n and sinZ n . (N/D 2014)

Text Book Page No.: 5.21 Video Explanations

6. Find the Z – transform of cosn and sinn . Hence deduce the Z – transforms of

cos 1n and sinn

a n . Video Explanations (N/D 2010)

Text Book Page No.: 5.21

7. Find cosZ n and hence deduce cos2

nZ

. (M/J 2013),(M/J 2016)

Text Book Page No.: 5.21

8. Find the Z – transform of 2

sin4

n

and cos2 4

n

. (N/D 2012)

Text Book Page No.: 5.24

9. Find the Z – transforms of cosn

a n and sinat

e bt . (A/M 2011)

Text Book Page No.: 5.21; 5.31

Page 21: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 21

10. Find the Z – transforms of cosn

r n and cosat

e bt . (M/J 2014)

Text Book Page No.: 5.38; 5.31

11. Find cosn

Z r n and sinn

Z r n . (A/M 2015)

Text Book Page No.: 5.38

12. If ( ) ( )Z f n F z , find ( )Z f n k and ( )Z f n k . (N/D 2011)

Text Book Page No.: 5.8

13. State and prove the second shifting property of Z-transform. (M/J 2013)

Text Book Page No.: 5.7

Inverse Z - transform by Partial Fraction

1. Find the inverse Z – transform of 2

10

3 2

z

z z . (N/D 2009)

Text Book Page No.: 5.41

2. Find the inverse Z -transform of 2

2

4 2

( 1)( 2)

z z

z z

by method of partial fraction.

Video Explanations

3. Find the inverse Z -transform of 3

2( 1) ( 2)

z

z z by method of partial fraction.

(N/D 2017)

4. Find the inverse Z – transform of

3

3

20

2 4

z z

z z

. (N/D 2009)

Text Book Page No.: 5.48

5. Find 2

1

2

2

( 1)( 1)

z z zZ

z z

and 1

( 1)( 2)

zZ

z z

. (A/M 2010)

Text Book Page No.: 5.45; 5.70

Page 22: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 22

6. Find 3

1

2

4

(2 1) ( 1)

zZ

z z

, by the method of partial fractions. (A/M 2017)

7. Find the inverse Z-transform of 2

2( 1)( 1)

z z

z z

, using partial fraction. (N/D 2014)

Text Book Page No.: 5.51

8. Evaluate 31

5Z z

for 5z . (N/D 2011)

Text Book Page No.: 5.52

Inverse Z - transform by Residue Theorem

1. Find the inverse Z-transform of ( 1)( 2)

z

z z using residue theorem.

Video Explanations

2. Find the inverse Z-transform of 2

3

( 5)( 2)

z z

z z

using residue theorem.

3. Find the inverse Z – transform of 3

( 1)

( 1)

z z

z

by residue method. (N/D 2010)

Text Book Page No.: 5.61

4. Evaluate

3

1

2

9

3 1 2

zZ

z z

, using calculus of residues. (N/D 2016)

5. Using residue method, find 1

22 2

zZ

z z

. (A/M 2015),(M/J 2016)

Text Book Page No.: 5.65

Inverse Z - transform by Convolution Theorem

1. Using convolution theorem, find the 1Z

of

2

4 3

z

z z . (N/D 2009)

Text Book Page No.: 5.77

Page 23: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 23

2. Using convolution theorem, find inverse Z – transform of 2

( 1)( 3)

z

z z .

(A/M 2011),(N/D 2013) Text Book Page No.: 5.76

3. Using convolution theorem, find the inverse Z – transform of 2

2( )

z

z a. (N/D 2012)

Text Book Page No.: 5.74

4. Using convolution theorem, find the inverse Z – transform of 2

1

2( )

zZ

z a

.

(M/J 2016)

5. Using convolution theorem, find 2

1

( )( )

zZ

z a z b

.

Text Book Page No.: 5.75 (N/D 2011),(M/J 2013),(M/J 2014),(N/D 2016)

Video Explanations

6. Using Convolution theorem, find the inverse Z – transform of 2

8

(2 1)(4 1)

z

z z .

(M/J 2012)

Text Book Page No.: 5.78

7. Using Convolution theorem, find 2

1 8

(2 1)(4 1)

zZ

z z

. (A/M 2017),(A/M 2018)

Text Book Page No.: 5.78

8. Using Convolution theorem, find

2

1

1 / 2 1 / 4

zZ

z z

. (A/M 2015),(N/D 2017)

Text Book Page No.: 5.78

9. Using convolution theorem, find the inverse Z – transform of

3

4

z

z

. (A/M 2010)

Text Book Page No.: 5.80

Page 24: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 24

Formation and Solution of Difference Equation

1. Form the difference equation from the relation .3n

ny a b . (N/D 2010)

Text Book Page No.: 5.83 Video Explanations

2. Derive the difference equation from ( 3)n

ny A Bn . (A/M 2011)

Text Book Page No.: 5.84

3. Form the difference equation form ( ) 2n

y n A Bn . (N/D 2013)

Text Book Page No.: 5.111

4. Form the difference equation of second order by eliminating the arbitrary constants A

and B from ( 2)n

ny A Bn . (N/D 2011)

Text Book Page No.: 5.85

5. Using Z-transform solve: 2 1

3 10 0n n n

y y y ,

01y and

10y .

(M/J 2013),(M/J 2014)

Text Book Page No.: 5.87

6. Using Z-transform, solve 2 1

3 2 0n n n

u u u given that

00u ,

11u .

(N/D 2014)

Text Book Page No.: 5.111

7. Using Z-transform, solve the difference equation ( 2) 3 ( 1) 2 ( ) 0x n x n x n

given that (0) 0x , (1) 1x . (A/M 2015)

Text Book Page No.: 5.111

8. Solve: 2 14 4 0

n n ny y y

, 0

1y , 10y , using Z-transform. (A/M 2018)

9. Solve the equation 2 16 9 2

n

n n nu u u

given 0 1

0u u .

Text Book Page No.: 5.91 (N/D 2009),(N/D 2012),(N/D 2016)

10. Using Z-transforms, solve 2 17 12 2

n

n n ny y y

, given that 0 1

0y y .

(A/M 2017),(N/D 2017)

11. Solve by Z – transform 2 12 2

n

n n nu u u

with 0

2u and 11u .(A/M 2010)

Page 25: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 25

Text Book Page No.: 5.112

12. Solve2 1

4 3 2n

n n ny y y

with

00y and

11y , using Z – transform.(N/D 2010)

Text Book Page No.: 5.111

13. Solve: 2 1

4 3 3n

n n nu u u

given that

0 10, 1u u . (N/D 2011)

Text Book Page No.: 5.112

14. Solve 2 1

3 2 4n

n n nu u u

, given that

0 10, 1u u . (M/J 2014)

Text Book Page No.: 5.93 Video Explanations

15. Solve the difference equation 2

2n n

y y , given that

00y and

10y by using

Z -transforms. (M/J 2016)

16. Solve ( 2) ( ) 1, (0) (1) 0y k y k y y ,using Z-transform. (M/J 2012)

Text Book Page No.: 5.96

17. Using Z-transform solve the difference equation2 1

2n n n

y y y n given

0 10y y . (N/D 2013)

Text Book Page No.: 5.98

18. Solve2

2 .n

n ny y n

, using Z-transform. (M/J 2012)

Text Book Page No.: 5.101

19. Using Z-transform, solve2 1

4 5 24 8n n n

y y y n given that

03y and

15y .

(N/D 2011)

Text Book Page No.: 5.112

20. Solve the difference equation ( 3) 3 ( 1) 2 ( ) 0y n y n y n , given that (0) 4y ,

(1) 0y and (2) 8y . (A/M 2011),(N/D 2012)

Text Book Page No.: 5.89

Page 26: Unit I (Partial Differential Equations)hariganesh.com/pdf/University Questions/uq_r17-tpde.pdf · Transforms and Partial Differential Equations 2018 Sri Hariganesh Publications (Ph:

Transforms and Partial Differential Equations 2019

Sri Hariganesh Publications (Ph: 9841168917, 8939331876) Page 26

Textbook for Reference:

“TRANSFORMS AND PARTIAL DIFFERENTIAL EQUATIONS”

Edition: 3rd Edition

Publication: Sri Hariganesh Publications Author: C. Ganesan

Mobile: 9841168917, 8939331876

To buy the book visit www.hariganesh.com/textbook

----All the Best----